Index: clang-tidy/llvm/HeaderGuardCheck.h
===================================================================
--- clang-tidy/llvm/HeaderGuardCheck.h
+++ clang-tidy/llvm/HeaderGuardCheck.h
@@ -14,6 +14,7 @@
 
 namespace clang {
 namespace tidy {
+namespace llvm {
 
 /// Finds and fixes header guards that do not adhere to LLVM style.
 class LLVMHeaderGuardCheck : public HeaderGuardCheck {
@@ -25,6 +26,7 @@
   std::string getHeaderGuard(StringRef Filename, StringRef OldGuard) override;
 };
 
+} // namespace llvm
 } // namespace tidy
 } // namespace clang
 
Index: clang-tidy/llvm/HeaderGuardCheck.cpp
===================================================================
--- clang-tidy/llvm/HeaderGuardCheck.cpp
+++ clang-tidy/llvm/HeaderGuardCheck.cpp
@@ -11,6 +11,7 @@
 
 namespace clang {
 namespace tidy {
+namespace llvm {
 
 bool LLVMHeaderGuardCheck::shouldFixHeaderGuard(StringRef Filename) {
   return Filename.endswith(".h");
@@ -49,5 +50,6 @@
   return StringRef(Guard).upper();
 }
 
+} // namespace llvm
 } // namespace tidy
 } // namespace clang
Index: clang-tidy/llvm/IncludeOrderCheck.h
===================================================================
--- clang-tidy/llvm/IncludeOrderCheck.h
+++ clang-tidy/llvm/IncludeOrderCheck.h
@@ -14,6 +14,7 @@
 
 namespace clang {
 namespace tidy {
+namespace llvm {
 
 /// \brief Checks the correct order of \c #includes.
 ///
@@ -25,6 +26,7 @@
   void registerPPCallbacks(CompilerInstance &Compiler) override;
 };
 
+} // namespace llvm
 } // namespace tidy
 } // namespace clang
 
Index: clang-tidy/llvm/IncludeOrderCheck.cpp
===================================================================
--- clang-tidy/llvm/IncludeOrderCheck.cpp
+++ clang-tidy/llvm/IncludeOrderCheck.cpp
@@ -14,6 +14,7 @@
 
 namespace clang {
 namespace tidy {
+namespace llvm {
 
 namespace {
 class IncludeOrderPPCallbacks : public PPCallbacks {
@@ -46,7 +47,7 @@
 
 void IncludeOrderCheck::registerPPCallbacks(CompilerInstance &Compiler) {
   Compiler.getPreprocessor().addPPCallbacks(
-      llvm::make_unique<IncludeOrderPPCallbacks>(*this,
+      ::llvm::make_unique<IncludeOrderPPCallbacks>(*this,
                                                  Compiler.getSourceManager()));
 }
 
@@ -163,5 +164,6 @@
   IncludeDirectives.clear();
 }
 
+} // namespace llvm
 } // namespace tidy
 } // namespace clang
Index: clang-tidy/llvm/LLVMTidyModule.cpp
===================================================================
--- clang-tidy/llvm/LLVMTidyModule.cpp
+++ clang-tidy/llvm/LLVMTidyModule.cpp
@@ -17,6 +17,7 @@
 
 namespace clang {
 namespace tidy {
+namespace llvm {
 
 class LLVMModule : public ClangTidyModule {
 public:
@@ -29,9 +30,11 @@
   }
 };
 
+} // namespace llvm
+
 // Register the LLVMTidyModule using this statically initialized variable.
-static ClangTidyModuleRegistry::Add<LLVMModule> X("llvm-module",
-                                                  "Adds LLVM lint checks.");
+static ClangTidyModuleRegistry::Add<llvm::LLVMModule>
+    X("llvm-module", "Adds LLVM lint checks.");
 
 // This anchor is used to force the linker to link in the generated object file
 // and thus register the LLVMModule.
Index: clang-tidy/llvm/TwineLocalCheck.h
===================================================================
--- clang-tidy/llvm/TwineLocalCheck.h
+++ clang-tidy/llvm/TwineLocalCheck.h
@@ -14,6 +14,7 @@
 
 namespace clang {
 namespace tidy {
+namespace llvm {
 
 /// \brief Looks for local Twine variables which are prone to use after frees
 /// and should be generally avoided.
@@ -25,6 +26,7 @@
   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
 };
 
+} // namespace llvm
 } // namespace tidy
 } // namespace clang
 
Index: clang-tidy/llvm/TwineLocalCheck.cpp
===================================================================
--- clang-tidy/llvm/TwineLocalCheck.cpp
+++ clang-tidy/llvm/TwineLocalCheck.cpp
@@ -16,6 +16,7 @@
 
 namespace clang {
 namespace tidy {
+namespace llvm {
 
 void TwineLocalCheck::registerMatchers(MatchFinder *Finder) {
   auto TwineType =
@@ -57,5 +58,6 @@
   }
 }
 
+} // namespace llvm
 } // namespace tidy
 } // namespace clang
Index: unittests/clang-tidy/LLVMModuleTest.cpp
===================================================================
--- unittests/clang-tidy/LLVMModuleTest.cpp
+++ unittests/clang-tidy/LLVMModuleTest.cpp
@@ -3,6 +3,8 @@
 #include "llvm/IncludeOrderCheck.h"
 #include "gtest/gtest.h"
 
+using namespace clang::tidy::llvm;
+
 namespace clang {
 namespace tidy {
 namespace test {